28 L. W. SACKETT 



in such tests, but little more will be attempted than to present 

 results, leaving the reader to make all direct comparisons desir- 

 able. Although Thorndike and Kinnaman have been the teach- 

 ers of us all in this kind of work, the apparatus was modeled 

 more exactly after that by Davis (14) as shown so admirably 

 in his study of the raccoon. The box itself was 11x12x16 inches 

 with a door six inches square in the middle of one of its sides 

 next to the ground line. This door was a light frame covered 

 with one -quarter inch mesh wire and was hinged at the bottom 

 by the inner edge in such a manner that gravity sufficed to 

 throw^ it open when the fastenings were released. The door 

 was made of wire in order to expose the food and give the porcu- 

 pine an added stimulus, but the result proved to be quite the 

 contrary as it led the animals to spend time struggling for the 

 exposed food, thus diverting their attention from the locking 

 devices. This reaction was most prominent during the first 

 efforts and it is probable that the character of the door was 

 non-significant after the experiment had proceeded a little ways. 

 The door was provided with "L" shaped projections on the 

 inner edge into which the locks could be adjusted when it was 

 closed. Locks and combinations used w'ere as follows: 



1. A simple push down lever was adjusted at the right-hand 

 end, extending about six inches, working in a groove in the 

 end of the box, and pivoted on the inner side of the front so 

 that when the projecting end was raised a little above the hori- 

 zontal, the door was fastened. 



2. A plug w^as adjusted in the top slightly toward the front 

 and right of the middle point. Attached by a string in the 

 end of the plug was a concealed lock similar to the lever. 



3. A horizontal thumb button four inches in length was placed 

 at the upper left-hand corner and adjusted to turn upward. 



4. A hook of the ordinary screen-door variety with the bend 

 taken out of the point was placed vertically near the upper 

 left-hand corner and made to open toward the left. 



5. The above four were placed in combination so that they 

 could not be operated except in the order named; i.e., enum- 

 erating in reverse order, the hook opened against the button 

 and consequently must come after it, the button was held by 

 an inside mechanism which was released only by pulling the 

 plug, while the plug in turn, was fastened until the lever w^as 



